12. Carbohydrates:

Question 1

Classification of carbohydrates:

Answer 1

digestible- non digestible 
classification is based on carbohydrates units
Glucose 1 MONOSACCHARADIS
sucrose 2 OLIGOSACCARIDES
starch many  POLYSACCHARIDES

Question 2

Main carbohydrates in food:

Answer 2

glucose, fructose, sucrose, lactose, starch

Question 3

Metabolism of carbohydrates:

Answer 3

digestion and absorption in the small intestine (glucose, fructose and starch that is break down by pancreatic amylase become monosaccharides)
fragmentation in the large intestine (lacotse, fructose, fermented by gut flora transformed into volatile fatty acids)

Question 4

Sugar transporters on enterocytes:

Answer 4

Glucose and galactose transported by sodium-glucose transport protein
fructose is absorbed via facilitated transprt GLUT5
all three transported in the bloos by GLUT2

Question 5

Carbohydrate malabsorption:

Answer 5

1. lactose intolerance
2. glucose-galactose malabsorption syndrome
3. fructose malabsorption

Question 6

Requirments carbohydrate:

Answer 6

brain needs 120 g glucose/d
pregnant and lactant lady: 175-210
body can produce glucose from protein and fat

Question 7

Carbohyrate storage:

Answer 7

Glycogen in the liver 100-120g
glycogen in skletal muscle (420 g)
when no more storage, glucose must come from diet or via gluconeogeesis

Question 8

Regulation of blood glucose concentration:

Answer 8

Pancreas secrete insulin, secrete glucagon

Question 9

What is diabetes mallitus?

Answer 9

Type 1 diabetes:
autoimmune destruction of pancreatic cells
not enough insulin is secreted
Type 2 diabetes:
Insulin resistence:
cellular insulin receptor not so sensitve
more insulin secretionrequired for same effect
less glucose homeostasis

Question 10

Elevate insulin level cause:

Answer 10

Hyperinsulinaemia
basal insulin concentration increase with age
associated with obesity and low physical activity

Question 11

What prevention of type 2 diabetes:

Answer 11

Decrease risk:
dairy products, whole grains, coffee, tea
Increased risk:
fruit juice, red meat, white rice, french fries
Physical activity is very important!!!

Question 12

Meal blood glucose response:

Answer 12

Test to help compare foods after increase of blood sugar after a meal

Question 13

Limitation of GI measurments:

Answer 13

amount of available carbohydrates very different in different products
inter-individual variation in glycemic response

Question 14

Factors influencing postprandial glucose response:

Answer 14

Type of starch
cooking or food processing
interaction with other nutrients

Question 15

Factor influencing digestibility of starch:

Answer 15

granular size 
crystalline structures (A,B,C )

Question 16

Interaction with starch an other nutrients:

Answer 16

granules can be enclosed in a protein matrix (pasta)

Question 17

Resistent starch:

Answer 17

physically inaccessible starch in whole grains
raw starch granules
retrograded starch

Question 18

Starch gelatization and retrogradation:

Answer 18

starch undergos swelling when heated in water, retrogradation when amylose and amylopectinechains realign
crystalline structures are formed after cooling

Question 19

Dietary fiber:

Answer 19

Intrinsic plant cell wall polysaccharides
Edible parts of plants that are resistent to digestion and absorption in the small intestine
Include polysaccharides, lignin, plant
Promote beneficial effect like laxation, blood cholesterol attenuation glucose attenution

Question 20

main components of dietary fibre:

Answer 20

Xylan 
dietary fibers that not digested promote other factors:
low glucose and cholesterol
resistence to CVD and colon cancer 
OAT b-GLUCAN

Question 21

Fermentaition in the colon

Answer 21

solube dietary fibre:
extensive fermentation by microflora in colon
formation of gases: high
growth of gut bacteria: high
Insoluble dietary fibre:
Minimal fermentation low gases and low gut bacteria

Question 22

Probiotics and prebiotics

Answer 22

Probiotica: living bacteria
prebiotics: non digestible food ingredietns that affect and stimulate growth and activity of bacteria

Question 23

Role of dietary fibre in colorectal cancerogenesis:

Answer 23

dietary fibre protect by modyfing colonic bacterial flora
being fermented create good environment less conductive to bacterial production of cancirogens
sppeding the rate of transit of colonic contents

Question 24

Low carbohydrate for lose weight?

Answer 24

keton bodies fuels for brain, muscle, heart
degradation of muscle proteins
unbalanced elecrolyte status

It takes a lot of carbo to promote lipogenesis

Question 25

risk associated with too high sugar intake:

Answer 25

nutriotionally unbalanced diet
obesity and diabetes
dental cries